Prognostic value of the pulmonary dead-space fraction in patients during the early phases of acute respiratory distress syndrome / 中华急诊医学杂志

ABSTRACT

ObjectiveTo evaluate the association between alveolar dead space fraction and the prognosis of patients with acute respiratory syndrome in the early phase ( ＜ 3 days).MethodsTwentythree patients with ARDS were enrolled in this study.The VD/VT was measured by the single breath test of CO2 (SBT-CO2).The age,heart rate,mean arterial pressure,APACHE Ⅱ,Murray lung injury score,functional residual capacity ( FRC ),PaO2/FiO2,tidal volume,airway plateau pressure ( Pplat ),static pulmonary compliance (Cst),28-day mortality were recorded.ResultsThe alveolar dead-space fraction was markedly elevated (0.59 ±0.06) and the mean FRC was markedly decreased (1643 ±409) ml in the early phase of ARDS.The mortality of 28 days was 52.2％.The mean dead-space fraction was significantly higher in non-survived patients than that in survival [(0.64 ± 0.08 ) vs.(0.53 ±0.04 )].VD/VT was correlated significantly with Murray lung injury score ( r=0.464,P =0.026).The area under the ROC curve for dead space fraction was 0.867,with sensitivity of 83％,and specificity of 82％.Conclusions Increased alveolar dead-space fraction of patients in the early phases of ARDS is associated with greater risk of death.